(1) Field of the Invention
This invention relates to signal processing through an electromagnetic device and, in particular, to system and method for signal amplification via the electromagnetic device without the use of power amplifiers, separate power supplies, and power inverters.
(2) Description of Related Art
Amplifying circuits are well known in the prior art and generally require a power amplifying stage. Such power amplifier circuits are illustrated in U.S. Pat. Nos. 4,409,559 and 4,651,112.
A typical class AB amplifier includes a power supply and an amplifier, both of which significantly increase manufacturing costs. Prior art circuits that avoid the requirement of a power amplifier are disclosed in the U.S. Pat. Nos. 4,763,080; 4,517,522; 4,047,120; and 4,453,131. Other conventional amplifiers such as the class D amplifiers always switch at fifty percent duty cycle even without application of any signal, which causes an inherent noise that increases the signal-to-noise ratio of a circuit. A more recently developed system that produces direct audio from a power supply is disclosed in the U.S. Pat. Nos. 5,986,498 and 6,392,476. The U.S. Pat. Nos. 5,986,498 and 6,392,476 relate to an off-line direct audio circuit that use a power supply and do not require a power amplifier output stage.
Regrettably, most conventional amplifying methods and devices use a dedicated power supply and power inverter circuits for the amplification of input signals, even if they avoid the use of power amplifier output stage. Therefore, it would be advantageous to have a highly efficient and effective circuit for amplifying input signals but without the requirement of having an expensive power amplifier stage, separate power supply, and power converters/inverters.